Double-wishbone and multilink suspension apparatuses are known as vehicle suspension apparatuses.
These types of suspension apparatuses have been widely adopted with design modifications to the suspension according to different applications.
Known as these vehicle suspension apparatuses are those in which a knuckle is supported with a damper unit, those in which input from a stabilizer is introduced into a lower arm, and those in which input from a stabilizer is introduced into an upper arm (for example, Japanese Patent Application Laid-Open Publication Nos. 2006-143013, 2000-153705 and 2006-182174).
FIG. 8 hereof shows the suspension apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2006-143013.
In a suspension apparatus 230, a damper unit (shock absorber) 231 is supported close to the knuckle, and the damper unit 231, which also doubles as a strut, has a fulcrum 234 for a link which extends to a stabilizer 233.
FIG. 9 shows the suspension apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2000-153705.
A suspension apparatus 240 is configured with the lower edge of a strut member 242 having a damper unit (shock absorber) 241 as a two-pronged fork 243. Each of these fork prongs 243 is coupled to a lower arm (lower link member) 244, and the edge of a stabilizer 245 on a wheel 246 is coupled to the lower arm 244 through the gap between the two fork prongs 243.
FIG. 10 shows the suspension apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2006-182174.
A suspension apparatus 250 has a knuckle 252 for rotatably supporting a wheel 251, an upper arm 253 for swingably coupling the upper portion of the knuckle 252 with the vehicle body, a lower arm 254 for swingably coupling the lower portion of the knuckle 252 with the vehicle body, a damper unit 255 extending between the lower arm 254 on the side of the knuckle 252 and the vehicle body, and a stabilizer 256 whose input is introduced into the upper arm 253.
For example, in a suspension system in which an A-shaped arm is used for the upper arm, and a damper unit whose spring is coaxial with the damper is mounted on the knuckle, as with the suspension apparatus shown in FIG. 8, there are numerous cases in which the stabilizer is attached to the lower arm, as in the suspension apparatus shown in FIG. 9, or in which the stabilizer is attached to the upper arm, as in the suspension apparatus shown in FIG. 10.
In a case in which the stabilizer is attached to the lower arm, it is sometimes difficult to introduce input from the stabilizer into the knuckle on the lower arm, the purpose of which is to avoid interference from the upper arm and damper, and the like. Here, when the ratio between the distance from the knuckle on the lower arm to the input point of the stabilizer and the distance from the input point of the stabilizer to the vehicle body side of the lower arm is designated as a lever ratio, the lever ratio deteriorates with increased distance from the knuckle on the lower arm to the input point of the stabilizer, and sometimes the action of the stabilizer cannot be adequately performed. Specifically, it is impossible to assure favorable handling stability.
In addition, in a case in which the stabilizer is attached to the upper arm, sometimes the input point must be offset forward or backward in relation to the axis (wheel center) in order to avoid interference from the lower arm, the damper unit, or the like. When the input point is offset forward or backward in relation to the axis, a mode occurs in which the knuckle itself is rotated, and unnecessary toe change occurs. Specifically, it is impossible to assure favorable handling stability.